summaryrefslogtreecommitdiff
path: root/crypto/zlib.c
blob: c9ee681d57fdf5dd6fb39081d4af3ad02be39d97 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
/*
 * Cryptographic API.
 *
 * Zlib algorithm
 *
 * Copyright 2008 Sony Corporation
 *
 * Based on deflate.c, which is
 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * FIXME: deflate transforms will require up to a total of about 436k of kernel
 * memory on i386 (390k for compression, the rest for decompression), as the
 * current zlib kernel code uses a worst case pre-allocation system by default.
 * This needs to be fixed so that the amount of memory required is properly
 * related to the winbits and memlevel parameters.
 */

#define pr_fmt(fmt)	"%s: " fmt, __func__

#include <linux/init.h>
#include <linux/module.h>
#include <linux/zlib.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/net.h>

#include <crypto/internal/compress.h>

#include <net/netlink.h>


struct zlib_ctx {
	struct z_stream_s comp_stream;
	struct z_stream_s decomp_stream;
	int decomp_windowBits;
};


static void zlib_comp_exit(struct zlib_ctx *ctx)
{
	struct z_stream_s *stream = &ctx->comp_stream;

	if (stream->workspace) {
		zlib_deflateEnd(stream);
		vfree(stream->workspace);
		stream->workspace = NULL;
	}
}

static void zlib_decomp_exit(struct zlib_ctx *ctx)
{
	struct z_stream_s *stream = &ctx->decomp_stream;

	if (stream->workspace) {
		zlib_inflateEnd(stream);
		vfree(stream->workspace);
		stream->workspace = NULL;
	}
}

static int zlib_init(struct crypto_tfm *tfm)
{
	return 0;
}

static void zlib_exit(struct crypto_tfm *tfm)
{
	struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);

	zlib_comp_exit(ctx);
	zlib_decomp_exit(ctx);
}


static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
			       unsigned int len)
{
	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &ctx->comp_stream;
	struct nlattr *tb[ZLIB_COMP_MAX + 1];
	int window_bits, mem_level;
	size_t workspacesize;
	int ret;

	ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
	if (ret)
		return ret;

	zlib_comp_exit(ctx);

	window_bits = tb[ZLIB_COMP_WINDOWBITS]
					? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
					: MAX_WBITS;
	mem_level = tb[ZLIB_COMP_MEMLEVEL]
					? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
					: DEF_MEM_LEVEL;

	workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
	stream->workspace = vzalloc(workspacesize);
	if (!stream->workspace)
		return -ENOMEM;

	ret = zlib_deflateInit2(stream,
				tb[ZLIB_COMP_LEVEL]
					? nla_get_u32(tb[ZLIB_COMP_LEVEL])
					: Z_DEFAULT_COMPRESSION,
				tb[ZLIB_COMP_METHOD]
					? nla_get_u32(tb[ZLIB_COMP_METHOD])
					: Z_DEFLATED,
				window_bits,
				mem_level,
				tb[ZLIB_COMP_STRATEGY]
					? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
					: Z_DEFAULT_STRATEGY);
	if (ret != Z_OK) {
		vfree(stream->workspace);
		stream->workspace = NULL;
		return -EINVAL;
	}

	return 0;
}

static int zlib_compress_init(struct crypto_pcomp *tfm)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	ret = zlib_deflateReset(stream);
	if (ret != Z_OK)
		return -EINVAL;

	return 0;
}

static int zlib_compress_update(struct crypto_pcomp *tfm,
				struct comp_request *req)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_deflate(stream, Z_NO_FLUSH);
	switch (ret) {
	case Z_OK:
		break;

	case Z_BUF_ERROR:
		pr_debug("zlib_deflate could not make progress\n");
		return -EAGAIN;

	default:
		pr_debug("zlib_deflate failed %d\n", ret);
		return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
		 stream->avail_in, stream->avail_out,
		 req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
}

static int zlib_compress_final(struct crypto_pcomp *tfm,
			       struct comp_request *req)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_deflate(stream, Z_FINISH);
	if (ret != Z_STREAM_END) {
		pr_debug("zlib_deflate failed %d\n", ret);
		return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
		 stream->avail_in, stream->avail_out,
		 req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
}


static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params,
				 unsigned int len)
{
	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &ctx->decomp_stream;
	struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
	int ret = 0;

	ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
	if (ret)
		return ret;

	zlib_decomp_exit(ctx);

	ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
				 ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
				 : DEF_WBITS;

	stream->workspace = vzalloc(zlib_inflate_workspacesize());
	if (!stream->workspace)
		return -ENOMEM;

	ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
	if (ret != Z_OK) {
		vfree(stream->workspace);
		stream->workspace = NULL;
		return -EINVAL;
	}

	return 0;
}

static int zlib_decompress_init(struct crypto_pcomp *tfm)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	ret = zlib_inflateReset(stream);
	if (ret != Z_OK)
		return -EINVAL;

	return 0;
}

static int zlib_decompress_update(struct crypto_pcomp *tfm,
				  struct comp_request *req)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	switch (ret) {
	case Z_OK:
	case Z_STREAM_END:
		break;

	case Z_BUF_ERROR:
		pr_debug("zlib_inflate could not make progress\n");
		return -EAGAIN;

	default:
		pr_debug("zlib_inflate failed %d\n", ret);
		return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
		 stream->avail_in, stream->avail_out,
		 req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
}

static int zlib_decompress_final(struct crypto_pcomp *tfm,
				 struct comp_request *req)
{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	if (dctx->decomp_windowBits < 0) {
		ret = zlib_inflate(stream, Z_SYNC_FLUSH);
		/*
		 * Work around a bug in zlib, which sometimes wants to taste an
		 * extra byte when being used in the (undocumented) raw deflate
		 * mode. (From USAGI).
		 */
		if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
			const void *saved_next_in = stream->next_in;
			u8 zerostuff = 0;

			stream->next_in = &zerostuff;
			stream->avail_in = 1;
			ret = zlib_inflate(stream, Z_FINISH);
			stream->next_in = saved_next_in;
			stream->avail_in = 0;
		}
	} else
		ret = zlib_inflate(stream, Z_FINISH);
	if (ret != Z_STREAM_END) {
		pr_debug("zlib_inflate failed %d\n", ret);
		return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
		 stream->avail_in, stream->avail_out,
		 req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
}


static struct pcomp_alg zlib_alg = {
	.compress_setup		= zlib_compress_setup,
	.compress_init		= zlib_compress_init,
	.compress_update	= zlib_compress_update,
	.compress_final		= zlib_compress_final,
	.decompress_setup	= zlib_decompress_setup,
	.decompress_init	= zlib_decompress_init,
	.decompress_update	= zlib_decompress_update,
	.decompress_final	= zlib_decompress_final,

	.base			= {
		.cra_name	= "zlib",
		.cra_flags	= CRYPTO_ALG_TYPE_PCOMPRESS,
		.cra_ctxsize	= sizeof(struct zlib_ctx),
		.cra_module	= THIS_MODULE,
		.cra_init	= zlib_init,
		.cra_exit	= zlib_exit,
	}
};

static int __init zlib_mod_init(void)
{
	return crypto_register_pcomp(&zlib_alg);
}

static void __exit zlib_mod_fini(void)
{
	crypto_unregister_pcomp(&zlib_alg);
}

module_init(zlib_mod_init);
module_exit(zlib_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Zlib Compression Algorithm");
MODULE_AUTHOR("Sony Corporation");